Liquid crystal displays have become an important display means, along with development of liquid crystal display technologies. And dynamic backlight technologies have been widely applied in liquid crystal displays. The liquid crystal display requires adopting dynamic backlight control technologies to drive a backlight source, thus allowing the backlight source to display images.
In the related art, a liquid crystal display has an image processing chip, a timing controller, a backlight driving module and a backlight source, where the backlight driving module has a backlight processing unit and a pulse width modulation (PWM) driver. After receiving video signals, the image processing chip conducts image processing to the video signals and outputs image data to the timing controller, and outputs synchronous signals and partition backlight data to the backlight driving module; the backlight processing unit of the backlight driving module generates duty cycle data and backlight current values according to the received synchronous signals and partition backlight data, and transmits the synchronous signals, the duty cycle data and the backlight current values to the PWM driver; thus the PWM driver is able to generate multiple paths of control signals according to the synchronous signals, the duty cycle data and the backlight current values; the PWM driver transmits the multiple paths of control signals to the backlight source, allowing the backlight source to perform optical display according to the multiple paths of control signals.
However, in the related art, the image processing chip performs other tasks, for example, searching satellite TV signals, while conducting image processing to video signals; the image processing chip functions in line with a multi-task processing mechanism. Therefore, frequency jitters with a certain magnitude will occur to synchronous signals transmitted by the image processing chip to the backlight driving module. FIG. 1 is a schematic diagram illustrating synchronous signals received and outputted by a backlight driving module in the related art, as shown in FIG. 1, number (1) in FIG. 1 is a schematic diagram illustrating synchronous signals transmitted by an image processing chip to a backlight driving module in the related art; number (2) in FIG. 1 is a schematic diagram illustrating synchronous signals transmitted by a backlight processing unit of a backlight driving module to a PWM driver in the related art. As shown in FIG. 1, the backlight processing unit of the backlight driving module also transmits the synchronous signals to the PWM driver, which accordingly generates control signals with frequency jitters; after the backlight source receives the control signals with frequency jitters, a backlight blinking phenomenon emerges when the backlight source performs optical display according to the control signals.